Flickering of screen

Currently I'm using macOS Sierra Version 10.12.4 on Macbook Air early 2015 model and the latest version of f.lux. Whenever I open my laptop from sleep in morning and it has to switch the modes, my screen flickers. Like between the color which was already there in night and the one which is available in normal mode. I don't know why? Earlier the transition used to be very smooth. Moreover it doesn't happen in evening when the dark mode sets in and screen starts to orang-ish in color.